Cam-driven pump



I June 16, 1925.

s. w. LUITWIE'LER cm nruvm'z Puflr Filed Jan. 11. 1923 3 Sheets-Sheet 1 S. W. LUITWIELER 0AM DRIVEN Pun? Filed Jan. 11, 1923 3 Sheets-Sheet 2 4 SAMUE S. W. LUIT WIELER CAM DRIVEN PUMP June 16 Filed Jan, ll, 1923 5 Sheets-Shae} 3 LWFEFE SAMUEL W- ATTORNEY cam.

Patented June 16, 1925.

SAMUEL w. LUITWIELER, ornocrrns'rnn, NEW YORK.

CAM-DRIVEN PUMP.

Application filed January 11, 1923. Serial No. 612,088.

T all whom it may concern:

Be it known that I, SAMUEL WV. LUrrwIELEn, a citizen of the United States of America, residing at Rochester, in the county of Monroe and State of New York, have invented certain new and useful Improve ments in Cam-Driven Pumps, of which the following is a specification.

My invention relates to a cam driven pump, and has for'its principal object to afford a practical and efficient form of double acting cam, capable of effecting a workin stroke in both directions, and thereby delivering a continuous'fiow' of liquid from the pump at substantially uniform velocity and pressure.

The invention has for a further object to afford a simple and economical mechanical arrangement that lends itself readily to the needs of a double-acting pump, and in which lubricating difficulties areeliminated.

The invention also comprehends certain other improvements and advantages, which will be apparent from the following detailed description when read inconjunction with the accompanying drawings, the novel char acteristics being pointed out. in the claims following the description.

In the drawings:

Figure 1 is a plan view of a pump constructed in accordance with one practical embodiment of the invention;

Figure 2 is a longitudinal vertical'sectional'view;

Figure 3 is a transverse vertical sectional view on the line 33 of Figure 2;

Figure 4 is a transverse vertical sectional view on the line 4-4 of Figure 2;

Figure 5 is a side elevation of the cam, showing in diagram its method of construction, and

Figure 6 is a diagram illustrating the work to be performed by one-half of the The structure illustrated in Figures 1 to 4 comprises in general a base or frame 1 to one end of which is secured a pump cylinder 2 which may be of any conventional type. 3 designates a vertical wall or partition, which together with the end walll affords a cam chamber 5 and a dripchamher 6, the latter located between'the pump cylinder 2 and the cam chamber 5, and constituting means for preventing access of fluid from the cylinder 2 to the cam chambe 5 into the pump cylinder or other suitable material Arranged within the frame 1 are guide rods 7 upon'which is slidably mounted a frame 8 carrying cam engaging rollers 9 and 10. In order to adjust said rollers into proper contact with the cam, the roller 10 is mounted in a plate 11 that is adjustable on the frame 8 by means of a set screw 12, and held in adjusted relationship on said frame by bolts 13. 14edesignates the cam, fixedly mounted on a cam shaft 15 and acting, as it rotates in engagement with the rollers 9 and 10, to reciprocate the frame8. The cam shaft-15 carries at its outer end a gear 16 engaged by a pinion 17 on the shaft 18, which carries a pulley 19 to which power maybe applied for driving the cam.

Connected with the frame 8 is a pump element,in the form of a piston rod 20 which extends through the drip chamber 6 and 2, where it carries a suitable piston that acts to force or compress liquid or fluid during its travel in both directions. The cam chamber 5 is adapted to contain a lubricating fluid up to a proper level for maintaining the cam and other moving cated state, and it is essential to prevent water or liquid in the pump cylinder 2 from gaining access to the cam chamber 5 in which the lubricating fluid is contained, and

thereby forming an emulsion which would be detrimental to the eflicient operation of the mechanism. This is accomplished by thedrip chamber 6, and any liquid that finds its way outside of the cylinder 2 around the piston rod 20, instead of entering the cam chamber 5, will drop to the bottom of the parts in a thoroughly lubridrip chamber 6, and can be drawn off there- I from through a drain valve 21. In order to effectually prevent any liquid onthe piston rod 20from working its way into the cam I chamber 5, I employ a gasket 220f rubber surrounding the piston rod 20 and held against the wall 3 by the attaching plate 23. The cam chamber is provided at its bottom with a pocket 25 within which the cam travels during its rotation, and 24 is top of the cam chamber 1, and which can be lifted off when it isdesired to replenish V the supply of lubricating fluid in the cam chamber. 7

Thecam 14 is symmetrical, and so formed as to positively actuate the piston rod 20 in a removable cover resting on,

both directions, both rollers 9 and 10 being in operative engagement with the cam at all points during its revolution. The shape of the double-acting cam is such as to impart very nearly uniform speed to the piston rod, and thus effect delivery of water or liquid from the pump in a continuous stream of substantially constant velocity and pressure.

To accomplish this, I employ a cam so shaped as to engage both rollers 9 and 10 throughout its rotation, the distance between the roller axes remaining always the same. Referring to Figure 6, the horizontal distances irom the zero point to 1, from 1 to 2, 2 to 3 and so on, represent equal periods in a half rotation of the cam, the line as repre-- sents the work to be performed by the cam, while the vertical lines 3/ represent the in creasing distances from the centre to the periphery of the earn, as required to perform the work represented by the line Radius a, Figure '6, represents the diameter of the selected rollers, radius '2) represents the stroke of the cam, and line to represents one-half the circumference of circle 0-, '6, Figure 5. v,

The cam is laid out by first selecting a center line a-c0, the cam axis of rotation, the'center of the roller nearest to said axis and the diameter of said roller. A circle is then described about the axis of the cam passing through the center of the roller, and the radii 1, 2, 3, 4, etc. are drawn at any given distance apart so as to divide the rotational movement of the cam into a reasonable number of units. Starting with radius 1 of Figure 5, a point is found on said radius by measuring beyond the circle a distance corresponding to the distance in Figure 6 from the point- 1 to the line Similarly with radius 2 in Figure 5, a point is found by measuring from the circle outwardly a distance corresponding to the distance in Figure 6 from point 2 to line 0. Continuing in this manner, a series of points are found on the radii 1 to 16, and such points are located beyond the circle at distances corresponding to the corresponding vertical lines y in Figure 6.

From the points thus formed, arcs are struck using a radius equal to the radius of the arbitrarily selected roller, and the curve of the cam is obtained by drawing a line tangent to these various arcs. b 0 represents the stroke of the cam, and d, d represents the positions of the two rollers at the beginning of a stroke. The other half is similarly formed, and a cam th'us constructed gives a working stroke in both directions, and produces a continuous flew from the pump, at practically uniform velocity and pressure. WVlnle there is a slight variation in the movement produced by the cam during the transition intervals between its opposite symmetrical curves, as indicated by the curves at the ends of line a: in Figure 6, this is counteracted by the increased peripheral speed of the cam at these points, so that there is no appreciable variation in the velocity and pressure of flow from the pump.

While I have described the invention with reference to a particular embodiment, I believe it to be new to provide a double-acting cam with a periphery so formed as to produce a practically continuous and uninterrupted flow of liquid at substantially constant velocity and pressure, and this ap plic'ation is intended to cover any adaptations of the invention coming within my improvement as set forth in the preceding description, "or within the scope of the following claims.

I claim:

1. The combination with a reciprocating pump element and a frame connected thereto, of a cam, rollers mounted on the frame and engaging the periphery of the cam at opposite points, one of said rollers being supported in a plate carried by the frame, and means for adjusting the plate on the frame so as to bring the roller into contact with the periphery of the cam.

2. The combination with a reciprocating pump element and a frame connected thereto, of a cam, rollers mounted on the frame and engaging the periphery of the cam at opposite points, one of said rollers being supported in a plate carried by and adjustable on the frame, and an adjusting bolt on the frame having engagement with a portion of said plate so as to hold the latter with the roller against the cam.

3. The combination with a reciprocating pump element and a frame connected thereto, of a reversible double-acting symmetrical cam cooperating with said frame and imparting a pumping stroke thereto in both directions, the cam having a flat base and a continuously curved outer end and acting through each 180 of turning to move said frame in one direction.

4. The combination with a reciprocating pump element and a frame connected thereto, of a reversible double-acting symn'ietrical cam cooperating with said frame and imparting a pumping stroke thereto in both directions, rollers mounted on the frame and engaging the periphery of the cam at opposite points, the distance between the axes of the rollers being substantially constant for any position, and the cam having a flat base and a continuous curve at its outer end and formed so as to effect continuous delivery of fluid at substantia/lly uniform velocity and pressure.

In witness whereof, I have signed my name.

SAMUEL W, LUITIVIELER,

hereunto 

